This application claims the priority of European Patent Application 02004596.9 filed Feb. 28, 2002, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a cooling arrangement for the rolling stand of a continuous casting system for heavy supports with spraying nozzles which can be acted upon by a cooling liquid and by compressed air through lateral supply pipes laid in the longitudinal direction of the rolling stand.
Cooling arrangements of this general type are known. FIG. 3 shows such an arrangement. Such pipe and nozzle arrangements for supplying the secondary cooling system of the continuous casting system, for a further development with two nozzles for each side, have at least three pipes. In this case, one pipe, for example, pipe L, supplies compressed air which is guided through a T-piece to both spraying nozzles D, and the two other pipes W supply the cooling liquid in the form of water to one of the spraying nozzles respectively. These three lines L and W extend parallel to the casting billet S which is to be shaped here into the shape of a double-T support within the rolling stand, in which various rollers R1, R2 and R3 shape the billet S. The spraying nozzles D are in each case arranged such that they spray into the gaps between adjacent rollers R1 and in this case, if possible, contact the entire lateral surface of the billet S with their spraying jet.
Since the feed pipes W and L extend parallel to the billet S, they have to be laid outside the respective segment frame. The supply with compressed air and water takes place by way of relatively thin lines L1 which have to be bent corresponding to the spraying direction. As illustrated in FIG. 3, for this purpose, at least three of the stub lines L1, of which two are bent, are required, as well as a distributor piece which is situated in-between and is provided here for the compressed air supply, but may also be provided for the water supply if compressed air is guided through the exterior pipes W.
The installation of such a pipe arrangement requires relatively high expenditures. A precise alignment of the spraying nozzles D with respect to the target surface of the billet S is difficult and, depending on the quality of the maintenance, there is also a considerable risk that areas of the billet S are acted upon which are to remain uncooled. In addition, the removal of an individual nozzle for maintenance purposes is not possible without the removal of the complete supply pipes W, L.
It is therefore an object of the present invention to further develop a cooling arrangement of the initially mentioned type such that its construction is simpler and operationally more reliable and that the mounting and installation expenditures can be kept as low as possible.
For achieving this object, it is provided in the case of a cooling arrangement of the initially mentioned type that only one cooling liquid and compressed-air pipe respectively is assigned to each rolling stand side, which are laid parallel to one another and are provided with connection points for the joining of connection plates which are fixedly connected with the spraying nozzles.
This further development requires only two pipes for supplying the secondary cooling system with air and water. Bent stub lines or distributor pieces, which are difficult to manufacture and require high expenditures, will therefore not be necessary. The flanging of a connection plate to the two supply pipes, which have corresponding connection points, is sufficient. These connection plates, in turn, will then already carry the correspondingly aligned or arranged spraying nozzles. As a result, the mounting or demounting becomes significantly simpler.
As a further development of certain preferred embodiments of the invention, the connection points at the supply pipes can be constructed as a flange to which the connection plates can be joined in a simple manner. It is also advantageous according to certain preferred embodiments of the invention to place the two supply pipes at a narrow distance from one another so that they can be provided in a simple manner with a joint connection flange for fastening the connection plates.
In principle, this results in the possibility to provide the connection flanges only on one side on the supply pipes and to provide a connecting link on the other side of the supply pipes, so that studs for mounting the connection plates can be guided through the space between the supply pipes and can be anchored in the connecting link.
However, it is also contemplated to provide the connection flanges on both sides on the supply pipes and to provide them with one connection thread for studs respectively for the flanging-on of the connection plates for certain preferred embodiments of the invention.
As a further development of certain preferred embodiments of the invention, the connection plate can be fixedly connected with two spacer pipes, of which one is connected with the compressed air and the other is connected with the cooling-liquid pipe, the spacer pipes ending in a flange which can be fixedly connected with the nozzle housing which is provided with two spraying nozzles situated at a certain angle with respect to the one another and to the axes of the spacer pipes. In this case, these spraying nozzles are connected in this housing with a mixing chamber and with ducts for guiding the compressed air and the cooling liquid. The connection plate also has passage openings to the spacer pipes which adjoin the connection flanges of the supply pipes in a sealed-off manner.
In the case of a variant of the invention, it may, however, also be provided that the connection plate itself is provided with a mixing chamber in the interior which, by way of connection ducts, is connected with the compressed-air and the cooling-liquid connection and has an outlet connection piece which is connected with a connection pipe piece to a spraying nozzle. In the case of this embodiment, the mixing of cooling liquid and compressed air can therefore take place within the connection plate and the spraying mixture will then be supplied to the assigned spraying nozzle or to several assigned spraying nozzles.
In this last mentioned embodiment, the connection pipe piece to the spraying nozzles can have a bent construction with respect to the laying plane of the supply pipes. It can also be detachably joined to the outlet connection piece and be provided with a protection against torsion which ensures that the connection pipe pieces to the spraying nozzles can be attached to the outlet connection piece only in a defined position. This further development therefore ensures the alignment of the spraying jet, so that an operator will not have to adjust this spraying angle by bending pipes in a high-expenditure manner. As a result, it is also possible to implement both spraying positions by means of an identical connection piece with a spraying nozzle.
The invention is illustrated in the drawing by means of two embodiments and will be explained in the following.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.